CN113389664A - EGR cooler core with concave round tube - Google Patents

Abstract

The application discloses take EGR cooler core of pit pipe for optimize the product structure, improve the life of product. The method comprises the following steps: a plurality of cooling pipes and connecting plates; the cross section of the cooling pipe is circular; both ends of the cooling pipe are fixed through the connecting plate, round holes with the same number as the cooling pipe are formed in the connecting plate, and both ends of the cooling pipe are fixed on the connecting plate through the round holes; the cooling pipe is provided with a plurality of pits, the size of the pits is the same, and the pits are used for increasing the contact area of the cooling pipe and the waste gas.

Description

EGR cooler core with concave round tube

Technical Field

The application relates to the field of internal combustion engine systems, in particular to an EGR cooler core body with a concave point round tube.

Background

An EGR (Exhaust Gas recirculation) cooling system is a system provided for reducing the emission of NOx from the Exhaust Gas of an automobile, and an EGR cooler in the EGR cooling system can reduce the temperature of the Exhaust Gas entering cylinders of the automobile, thereby reducing the temperature of the engine.

In a common EGR cooler in the prior art, a cooler core body is generally in a flat tube structure and is formed by plugging cooling fins in flat tubes, wherein the surfaces of the cooling fins need to be coated with nickel bases by roller and then are placed in a vacuum brazing furnace for brazing. The structure of the flat pipe has the following two defects:

first, flat pipe is usually formed by steel sheet crimping welding, and the flat pipe welding position easily produces stress concentration.

Secondly, when the inner cavity of the flat tube is small and the cooling fin is inserted, the nickel base on the surface of the fin is easy to scrape off, and sufficient welding flux cannot be ensured between the cooling fin and the flat tube during brazing; when the inner cavity is larger in brazing, the nickel base cannot be adsorbed on the contact surface of the cooling fin and the flat pipe through the capillary action due to overlarge fit clearance. The two conditions can generate a false welding phenomenon during welding, so that a cooler core is bulged or cracked, and the product has hidden trouble in reliability during operation, so that the assembly difficulty among parts is high, the manufacturing manufacturability of the product is poor, and the yield is low.

Disclosure of Invention

The application provides a take EGR cooler core of pit pipe for optimize the product structure, improve the life of product.

The application provides an EGR cooler core of area concave point pipe includes: a plurality of cooling pipes and connecting plates;

the cross section of the cooling pipe is circular;

both ends of the cooling pipe are fixed through the connecting plate, round holes with the same number as the cooling pipe are formed in the connecting plate, and both ends of the cooling pipe are fixed on the connecting plate through the round holes;

the cooling pipe is provided with a plurality of pits, the size of the pits is the same, and the pits are used for increasing the contact area of the cooling pipe and the waste gas.

Optionally, the apertures of the circular holes are the same and the pitch between the circular holes is the same.

Optionally, the circular hole is formed by high-precision blanking.

Optionally, a section of step is symmetrically arranged at two ends of the cooling pipe, the diameter of the step is smaller than that of the cooling pipe, and the step is matched with the connecting plate to limit the cooling pipe.

Optionally, the diameter of the tail end of the step is larger than that of the round hole, so that an opening expansion connecting portion is formed at the tail end of the step and is used for being matched with the round hole to fix the cooling pipe on the connecting plate.

Optionally, the cooling pipe and the circular hole are assembled in a clearance fit manner.

Optionally, the pits are formed by stamping.

Optionally, the cooling pipe and the connecting plate are connected by vacuum brazing.

Optionally, the material of the cooling pipe is stainless steel 310S.

Optionally, the material of the connecting plate is stainless steel 310S.

According to the technical scheme, the method has the following advantages:

1. the EGR cooler core body is made of the cooling pipe with the round pipe structure with the concave points, the product structure is optimized, the cooling fins are not plugged in the flat pipes, and the risk of bulging or cracking of the cooler core body is reduced.

2. The cooling pipe of pipe structure contacts evenly all around, does not have closed angle and transition point, and welding effect is better, and intensity is better, improves the life of product.

3. The working procedures of assembling the cooling fins and coating nickel base on the cooling fins are eliminated, the assembling working procedures and the process route are optimized, the production cost is reduced, and the production efficiency is improved.

Drawings

In order to more clearly illustrate the technical solutions in the present application, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is a schematic diagram of an EGR cooler core with a dimpled circular tube according to the present application;

FIG. 2 is a schematic diagram of a connecting plate of an EGR cooler core with a round tube with concave points according to the present application;

FIG. 3 is a schematic diagram of a configuration of cooling tubes in an EGR cooler core with dimpled round tubes according to the present application;

fig. 4 is a schematic partial structural view of a connecting portion between a cooling tube and a connecting plate in an EGR cooler core with a round concave tube according to the present application.

Detailed Description

The application discloses take EGR cooler core of pit pipe for optimize the product structure, improve the life of product.

In the present application, the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are used only for explaining relative positional relationships between the respective members or components, and do not particularly limit specific mounting orientations of the respective members or components.

Moreover, some of the above terms may be used to indicate other meanings besides the orientation or positional relationship, for example, the term "on" may also be used to indicate some kind of attachment or connection relationship in some cases. The specific meaning of these terms in this application will be understood by those of ordinary skill in the art as appropriate.

Furthermore, the terms "mounted," "disposed," "provided," "connected," and "connected" are to be construed broadly. For example, it may be a fixed connection, a removable connection, or a unitary construction; can be a mechanical connection, or an electrical connection; may be directly connected, or indirectly connected through intervening media, or may be in internal communication between two devices, elements or components. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In addition, the structures, the proportions, the sizes, and the like, which are illustrated in the accompanying drawings and described in the present application, are intended to be considered illustrative and not restrictive, and therefore, not limiting, since those skilled in the art will understand and read the present application, it is understood that any modifications of the structures, changes in the proportions, or adjustments in the sizes, which are not necessarily essential to the practice of the present application, are intended to be within the scope of the present disclosure without affecting the efficacy and attainment of the same.

Referring to fig. 1-4, an embodiment of an EGR cooler core with a dimpled circular tube provided by the present application includes: a plurality ofcooling pipes 1 and connectingplates 2;

the cross section of thecooling pipe 1 is circular;

both ends of thecooling pipe 1 are fixed through the connectingplate 2, the connectingplate 2 is provided with circular holes with the same number as thecooling pipe 1, and both ends of thecooling pipe 1 are fixed on the connectingplate 2 through the circular holes;

thecooling pipe 1 is provided with a plurality ofconcave points 3, theconcave points 3 are the same in size, and theconcave points 3 are used for increasing the contact area of thecooling pipe 1 and the exhaust gas.

This application changescooling tube 1 into the pipe structure by traditional flat tubular construction to evenly set upconcave point 3 oncooling tube 1, thereby increased the area of contact of cooling tube and waste gas, improved cooling efficiency from this. It should be noted that the number and the spacing of thepits 3 on thecooling tube 1 are not limited herein, and the specific number and the spacing may be determined by heat dissipation calculation according to different usage scenarios. The circular holes on the connectingplate 2 can be selected according to the size of the connectingplate 2 and the number and diameter of thecooling pipes 1, and then the proper hole pitch and the proper hole diameter are selected through calculation and analysis.

Optionally, the apertures of the circular holes are the same and the pitch between the circular holes is the same.

When round holes on the connectingplate 2 are manufactured, the same pitch of each round hole is required to be ensured, so that the strength of the connectingplate 2 is ensured, and the stress weak point of the connectingplate 2 is avoided.

Optionally, the circular hole is formed by high-precision blanking.

The round hole on the connectingplate 2 can be manufactured by high-precision blanking, and the dimensional tolerance precision is 0.05 mm. By adopting the high-precision blanking processing technology, the size precision required by vacuum brazing between thecooling pipe 1 and the circular pipe can be ensured while the production efficiency of the product is improved.

Optionally, a section ofstep 4 is symmetrically arranged at two ends of thecooling pipe 1, the diameter of thestep 4 is smaller than that of thecooling pipe 1, and thestep 4 is matched with the connectingplate 2 to limit thecooling pipe 1.

The both ends ofcooling tube 1 are provided with thestep 4 of a segmentation respectively to the symmetry, and the diameter ofstep 4 is less than the diameter ofcooling tube 1, consequently assembles throughstep 4 and connectingplate 2, can play spacing effect to coolingtube 1.

Optionally, the diameter of the end of thestep 4 is larger than the diameter of the circular hole, so that the end of thestep 4 forms a mouth-expanding connection portion, which is used for matching with the circular hole to fix thecooling pipe 1 on the connectingplate 2.

When carrying out the assembly ofcooling tube 1 and connectingplate 2, penetrate the round hole on the connectingplate 2 withstep 4 on a plurality ofcooling tubes 1, after whole assembly, rise the mouth with the toper with the end ofstep 4 and rise the mouth, form and rise a mouthful connecting portion, can enough guarantee like this thatcooling tube 1 can not loosen and take off, can eliminate the clearance betweencooling tube 1 and the connectingplate 2 again to reach the required assembly gap of brazing, improve the qualification rate of brazing.

Optionally, thecooling pipe 1 is assembled with the round hole by clearance fit.

The assembly between the round holes on thecooling pipe 1 and the connectingplate 2 adopts micro clearance fit, so that the assembly efficiency can be ensured, and the clearance required to be reserved for vacuum brazing can be ensured.

Alternatively, thepits 3 are formed by stamping.

Alternatively, the coolingtube 1 and theconnection plate 2 are connected by vacuum brazing.

The concave points on thecooling pipe 1 are welded in a vacuum brazing mode between the coolingpipe 1 and the connectingplate 2 through punch forming, the vacuum brazing is suitable for welding between devices of complex and narrow channels, the yield of products can be improved, the production cost of the products can be reduced, the corrosion resistance of the products is improved, and the vacuum brazing method is suitable for large-scale application.

Optionally, the material of thecooling pipe 1 is stainless steel 310S.

Optionally, the material of the connectingplate 2 is stainless steel 310S.

In summary, the present application has the following advantages:

1. the EGR cooler core body with the round tube structure with the concave points is adopted, the product structure is optimized, the cooling fins plugged in the flat tubes are eliminated, and the risk of bulging or cracking of the cooler core body is reduced.

2. Thecooling pipe 1 adopts the pipe structure to make thecooling pipe 1 contact all around evenly, does not have closed angle and transition point, and welding effect is better, and intensity is better, helps improving the life of product.

3. The working procedures of assembling the cooling fins and coating nickel base on the cooling fins are eliminated, the assembling working procedures and the process route are optimized, the production cost is reduced, and the production efficiency is improved.

The above embodiments are only used to illustrate the technical solutions of the present application, and not to limit the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions in the embodiments of the present application.

Claims (10)

1. An EGR cooler core with a pit round tube is characterized by comprising: a plurality of cooling pipes and connecting plates;

the cross section of the cooling pipe is circular;

both ends of the cooling pipe are fixed through the connecting plate, round holes with the same number as the cooling pipe are formed in the connecting plate, and both ends of the cooling pipe are fixed on the connecting plate through the round holes;

the cooling pipe is provided with a plurality of pits, the size of the pits is the same, and the pits are used for increasing the contact area of the cooling pipe and the waste gas.

2. The EGR cooler core according to claim 1, wherein the bore diameters of the round holes are the same and the pitch between the round holes is the same.

3. The EGR cooler core according to claim 1, wherein the circular hole is made by a high-precision blanking process.

4. The EGR cooler core according to claim 1, wherein the cooling tube is symmetrically provided with a step at both ends, the diameter of the step is smaller than that of the cooling tube, and the step cooperates with the connecting plate for limiting the cooling tube.

5. An EGR cooler core according to claim 4 wherein the diameter of the distal end of the step is larger than the diameter of the circular hole, such that the distal end of the step forms a flare connection for cooperating with the circular hole to secure the cooling tube to the web.

6. An EGR cooler core as defined in claim 1 wherein said cooling tube is a clearance fit with said circular hole.

7. The EGR cooler core according to claim 1, wherein the dimples are formed by stamping.

8. The EGR cooler core according to any of claims 1 to 7, wherein the cooling tube and the web are connected by vacuum brazing.

9. The EGR cooler core according to any of claims 1-7, wherein the material of the cooling tube is stainless steel 310S.

10. An EGR cooler core according to any of claims 1 to 7 wherein the material of the web is stainless steel 310S.

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